Telephone-exchange system



Oct. 16 1923.

A. E. L UNDELL TELEPHONE EXCHANGE SYSTEM Filed Sept; 8; 1920 25 tabli'shed.

Patented Oct; I6; 1923.

c UNI ED .sTAmamami:mace;

Y "ALBEN E LUNDE or 1\T EW YORK, n.1, Assre voR TO WESTERN LncrnIccoMPANY;

- INCORPORATED, ornnwyonm v y n oonronn'rronor NEW' ORK;

i frnLEP oNE nxcnANGE sysrnmh f I I I v mplication file'd 'sep temher s 1920; e rn Nc. ioeesaQ 1 To a ZZfwhorr zict ma aomm: la switching device-associated,lwithflthe link Be t known that VVL'TALBEJN. E. circuit and controlled by meansof; impulses acit'izen of the jUnitedStates, res d ng at suppliedover the terminalsof anqoutgoing NeWYo'rk; in the countyof New York, State v v p 5 of New Yorlnhaveinvented certain new and assoc1ated.;,,The number of iinpulsessupe so useful Improvements '7 in Telephone-.Ezrpl1ed to theiswitching devicejwill' vary "in change Systems,' oifwhich the following is accordance with theparticular outgoing line i a full, clear, concise; and exact description. 1 Wh ch'has' been selected; Diflerentnumbers v -This-1nvention relates to telephone eX- OfHHpHl SQS 'WIllbG supplied to the terminals"- li'ne with which the link circuityhas been v- 10 change systems and morefllparticularly to ofoutgoing lines to "characterize these'lines a s stems in which a link circuit with which with respect to vthei transmission qualities, a repeating coilis associated isused for ex- It is thought thatthe invention willv best tending connections to oints at varying be understood from thefollowing-detailed distances, a a a description, reference being hadtd theac-i V In "systems of the above mentioned type, 'companyingl drawing. ,2 I

it is desirable thatrdevices be providedby In the drawing,thefi gurelshowsso "much means of which the ratio of the number of of a telephone system as is necessary to fan turns of the secondary winding 10 thenumunderstanding of the invention.

, ber of; turns of the primary .Winding ofthe The invention has been. shown applied tor, repeating "coilinay be made, variable. This a semi-automatic.system employing power 75 is necessary t in order that proper transmisdriven switches, bu't since itii'sobviouslyca f sion may be accomplished irrespective'of the" pable' o fadaptation to "many types otteleimpedance characteristics of loading; of phone systems it is notto belimited ,to the V Qtheline to which connection has been es-g system as; disclosed, l

In certainv systems: in which means have When theYsubs'cribe-rvat,thesubstation "1' I vThe operation ofthesystem is aslf ollowsz' it I been provided for varying the ratio ofv the Jijemoves', hisjreceiver from the f switch hook, I

repeatingccoil'yvindjfigg, thej result haslbee'n 'ClIjQllllilS 'fIfO I Ii gIfiOlilIlded bataccoinplished under the'jcontrol of the send 'te1'y,;left hand 'winding of line relay- 2,

I 9 er as aresult ofaselective operation of'an: outerfarmature and back contact of cut-off 85 automatic switch. This type of operation relay 8, through theclosed loop of thecan places'an additional burden we e sender i'ng subscribers line inner a matur and since it tends to complicatethe sender cir back contact ofrelayB, right hand winding cuitsl In additioman extra time interval is of line, relay 2 to round: Belay2 is 'enq required inwhichto accomplish :the neces--j ergized and completes a Cir OUltlfIQm ground- 90 a sary selectivefoperation.

ed battery, lampj lr right hand armature In systems such as' hat shownin my' coandffrontfcontact ofrelay 2togroundl The pending application Serial No; 408,851, freshm n illumination'oflamp 4 informs filedSeptember 8, 1920, theselection of a dethe operator that the associated line is 'call- 40 sired repeating coil ratioisaccomplished in ing. Shethereuponinserts answering plu 95i accordance with distinctive electrical char 5 into jack :6 whereupon a circuityis'comacteristics of the outgoing 'li ne s to which pleted from groundedbattery,winding of the link circuit has access. 'relay7', sleeve contacts'ofplug o andjack 6,

his the object of thisinventionito proi winding of cut-jolt relay 3 to ground. Re:

I vide' an improved means for varying the lays? and 3 are energizedin this circuit. 1

ratio of the windings ofa repeating coil ilIl Relay 3, 1pon energizing, opens the ciraccordancewith distinctive. electrical char-Q cuitof line relay 2 and this'relay de-enon acteristics of the trunks to which" it has gizes,'jcausing lamp 4x0 be extinguished, I access. f Y i The loperatorthen depresses listening key It is a further object of this invention to 8, wherenponjher telephoneheadset is con- 105 1 provide means which shall'be simple and efnected to the calling line. "The calling subficient 'andby'means of'which a'wide range vscriher may nowconverse with theoperator of variation of the repeating coil winding and inform her of the number of the wanted ratio may be obtained, V

"line. I

I A feature'of thc'inv'ention" theus'e of The'cord circuit used the operator 1"" terminates atone end in an answering plug and in the other :in, an} automatic switch. In: order to simplifythe disclosure, it has been assumed that the switch shaft has mounted nponit but oneset of brushes and that this setof brushes serves a contact bank containing the terminals of 100 trunk llnes arranged in 10 groups of 10' trunks each.

The mechanical structure. of the switch is a readily understood simplification of the 500 point switch, shown' in Patent No.

' 31,123,696 issued Ja-n; 5'," 1915,: B. Graft d sm her ofthe wanted line, depresses keys in a cord circuit by means of a cord finder. The

lVhen' the sequence switch which controls'sequence"switch contacts 9 "'pleted froin grounded battery, winding of relay 11, lower "right hand contact of seq I "qunce switclrspring- 12, conductor ar 2 mature and backcontactof the O counting 'relay, winding otstepping.maghet14gcon ntact pf sequence switch spring ound. iRelay's jll land-14L arefener 1gi z'ed in' this circui't a n'd relay 11, upon en erg-12mg, locks?upfthrough its left hand ar:- mature and front contact and the lower left handcontactofse'quence switch spring 12 E'togroundedconducton13L] I -Relay" -.1'1at its right hand armature and front contact completes a circuit from grounded I battery, jpower magnet of se- 1 Q'quenc'e switch 17 upper contajcto'f sequence switch springlS, right hand armature and front contact of relay 11 to ground, for "mov ng thls sequence w tch out. of poslt on 1 and into position 2.

In position 2 of sequence switch 17am icuit is completed ffromi grounded battery, .winding f the up drive magnet 19, upper contact of sequence switch spring-20, right hand armature and front contactof relay 11' "toground, 'The. energization of magnet 19 causes the brush shaftto be moyed up-" iwardly.' As soon'as commutator brush 21 theffirst" conducting segment of cominutator 22 a circuit is completed fromgrounded battery; winding of, relay 11, left "'"hand armatureand front contact of: relay 1 1 lower left handandfupper right hand 7 rush 21 to ground.

p v (not shown), 'ZISSOClLtQd with the sending device, and 5 30- and 10,,reacheslposition 2, a circuit is. comequences i-tch sp in 9, conductor sition 8.

contacts of sequence switch spring 12 conductor23, commutator 22," commutator Stepping magnet 14: is shunted'down due to the fact that relay 11 has nowfoundia direct path .toground. As

the brush 'shaftis movedu'pwardly, relay 14 v is intermittently energized to control the op- 'erationoit the counting relays in the well known manner. .l Vhenthe O counting re,- iay isen'ergized', the clrcuit through Stepplng magnethfis permanently opened and when, amoment later commutator brush 21 engages an nsulatlng 'se'gment of commutator22, relay-11isde energiz'ed and conipletes a i c ircuit;jfrom "grounded battery,

power magnet of"sequenceswitch 1' 7, the

lowerleft hand contact.of sequence switch tact ofrelay 11 to groundftor moving. this seqnenceswitch outi'ofpos'ition 2 and into.

position 1.} The de-energization of relay 11 net 19, thus causing; the brush shaft tocome to rest withithe brush 'se't-engagino the eonfirst trunk 1n the selected tact set of. the g p-1' r It will 'be assumed'that the' second group of" trunks hasbeenselecte'd. If the first trunlcin-Kthe Q'roupis busy this iactwill be indicated" by the presence of ground. potential on thetcst terminal of such trunk. A circuit is thereupon completed from grounded battery, I winding o'l rfelay 11, upper con tactfof sequence-switch spring 27, test brush '25, test terminal 26, and thence to g'round 11' islenejrgized in this "circuit' and completes soon test brush .25, en'gagestest terminal 28, which is associated with the firstidle trunk intli'e group. relay l1de-enernizes,

since no groundpotential is found on such test terminal. The de-energ'lzat on of relay,

.1 opens, the circuit of up. ,driyemagnet .19, and causes'the brush set to be brought to rest on the terminals of the idle trunk The deenergizationof relay 11 also completes; :1

circuit extending; from grounded. battery. power magnet ofsequenceswitch ,17,lower lettt hand contact of sequence switch spring .18. right .hand armature and back contact. of relay 1.]. ton-round. for moving this sequence switclro'ut of posjtion4 and into posoon as;seq uence switch17 reaches p o siltlon}, jgroundpotentml is supplied to test terminal 28 by w y. of test brush 25and the lower contact of sequence switch spring 18, the. right hand armature and back conalso opens the circuit of. the up drivemag way of sequenceswitch contact, co'rrespending to contact 27, associated with the switch which has seized suchtrunk.v 1 Relay a circuit; from grounded battery, .winding of 'updriyef magnet 19, {upper contact. of sefquence, switch spring 20, right:hand .arma- .;ture and'frontcont-actofrelay11 to ground. 'lihe brush shaft is now. again moved upwardlyiina:t1'11'nk'lii1nting movement, .A sg

" tactof relay 245 and sthe, upper' armature 27 to render the trunk non-selectable to other hunting selector switches.

In position S of :sequence switch '17; th auxiliary switch which; controls the selection of a desired repeatingcoil ratio isbrought into operation under fthe control of the in- V stored to itsnormal" position'by continuing rotation until its: normal position iSf reached.- :The mechanical structure of 'thisswitchfis w r preferably similar to that shown in artapplication' of O. F. Forsburg and BkMx De Vignier, Serial 'No. 317,126, filed August13, 1919. "The interrupting devicecomprises a plurality of impulse wheels mounted on aflay66'to ground 'for moving this sequence ,switchoutof position8 and into positionlO. T

common shaft and continuously rotated by means of any desired form of prime mover.

- As-soon as the projectionon pick-up. in:

terrupter wheel 67 engagesi the contact and back contact of relay 24,;winding of.

relay 24, lower armatureandback contact of relay '29, terminal 40; brush 39,xlower contact of. sequence switch spring 42 to ground; Relay 24-:isener'gized: in thiscir- 'cuit and locks up w r circuit extending I from grounded battery,: sinner, upper arma ture, and its make-before-breakf contact,

winding of relay 24 t o ground over the" path described. r

V impulse conductor 70 to terminal 30byfway of the outer upper'arma'ture and front con-j V and backicontactcf relay 29;'-

. Stepping magnet is now energized andf de-energized*-three times under the 1 control of impulse wheel 71, it 'beingnoted that wheeli7 1 is arrangedto send three impulses.

1f a-trunk in the first grouplhad been selected, impulse conductor 72 would-h'ave been connected through to control stepping magnet 65 and only one iimpulse would' have been sent-.1 (Only three, ofi normalposi v sitions ofthe auxiliary eswitch have been indicated in the drawing, but itis obvious 6d mag'netj65, winding :of. slow; release v:relay that any numberl'of positionscouldbeused and the impulsewheel may be arranged :to

send any desired 'numberof impulsesl ,The. first closure of impulse. lead to 66, upper right hand contactlof sequence switch spring- 33, conductor 32, brush-31,

. terminal- 30, upper armatureiand backlcon-' tact' 'of relay 29, outer. upper armature and w front contact of 'relayl24,' conductor;v 70, jcontact 73 L to ground; f Stepping magnet 65 and relay'fiti are energized in this circuit.

Asjsoon as the' circ'uit of magnet 65 "is opened, which occurs on the first opening of v the contact 73', this magnet isde-energ'ized and causes the auxiliary switch to advance" itswipers-one step." Relay 66 beingfslow' 1 to release remains energized until the termination of the'series of impulses;- 1

an off-normal contact servedby wiper "75, 7 wiper 175, "armature'and back contact ofre- I 1 Itois to be noted "that when relay24w'as L Bela-y. :36 upon energization lock up through its armature and front contactqto energized, :it completed at its lowerjarmature anvenergizing circuit for sleeve relay spring associated with: this wheel, a circuit is completed jfromgrounded battery,rcon-;

d tact 68, conductor 69, upper inner armature groundbylwayofterminal'28, brush 25 and switch spring .42. :The 'de-ener'gization of- :relay 24: completes a circuit extending from groundedbattery," winding of {relay 295.,

lower armature and back 'contacjt of relay V r I a 1 I *24, armature and front contact ofrelay 36 i a I 7 Then energization of relay- 24c connects to ground as described. (Relay 29 is energized and by attracting its armatures con- 7 V nects the; tip and ring; conductors through ,to'the maintipandring conductors 37 and 38 ofthe selected trunk;

hen sequence [switch 17 comes to rest lin position 10, the fundamentalfcircuit is extended to the succeeding switch in the train; The fundamental circuit may be,

traced from trunk conductor 37 upper arthe"*lower f contact of" sequence" switch -spring W Assoon as sequence switch 17 leaves positioni S, relay- 24- isde-lenergiaed due to the. oiopening of-the ilower contact of sequence; 7

mature'andfront contactofrelay 29,'terarmature and back contact of the 0" countsequence switch spring9, conductor 15, up-

-minal*30,' brush 31, the lower contact of 3 sequence switch spring 33, conductor 13,v

aper contact of sequence switch spring 16,1;

brush 39, terminal 40, lower armature and a ont contact ofrelay 29 to ring trunk con .120 o ductor 38. l Succeeding switchesin the train I V are actuated in the well known manner 1111- I.

der;-the control of the sender." The como pletion' of "each selective operation willfi Y cause the advance of thesendersequence' switch andwhen the sender sequence switch f reaches positionqlhat which time itwill be assumed that all selective operations of vthe; switches have beenfcompletedya air-2. cuit is 'completed from grounded battery;

7 talking connection is completed ati-the dis- ..Tli'e c district; repeating" coil may then. be I traced Ifrom.;grounded, battery, lower right hand .winding. of; repeating coil :45, it: being ob served that -a minimum, number of v turns power'magnet of "sequence switch 17 ,"con

tact of sequence switch spring, 41, contact of position 10 and intoposition 16. 1 j r In position lfi of-sequence switch 17, the

trict switch by means of-closures atsequence o, switchY1springsg33and 42. ;Assu-ming'xthat the called subscriber Q has answered," supervisoryrrelay' ti Wlll have -been-.;cnerg1zed; ut of the secondary winding :oithe are; included, switch wiper 76and itsthird off-normal contact, winding of, supervisory arelay; 44, upper contact of sequence switch spring 42, brush '39, armature and front contacts-of relay 29,.

v trunlcconductor138,?lower leftliandwvinding 5acterized z byqhaving an iinpu'1se lead conv- --of repeating coil 16, armaturerrand front contact of relay43 resistance 47,-up'per left I. fhandrwinding of repeating: coil 16, --trunk l conductor, 37,; upper armature and :front icontact of-yrelay 29, terminal 30,: :brush' 31,

'conductorf32, upper left handjcontact of sequence switch spring 133., switch-wiper 77 rand its tlnrd; ofllnonmal' contact --'and the upper right-hand winding of repeating coil fj nection suclithattln'ee impulses will be supplied; to: the: auiriliary'fswitch, 'willresult in V t-he' selection-of the minimum ratio of the j nfumberwofturns in the secondaryfwinding of repeating coil 15 to those inithe primaryfwinding. a 3 r The connection" havingbeen 7 completed; the'; subscribersmay now; converse, it being w noted that callingsupervisory ,relay 1 18 we both: calling and calledsubscribers will re- ;place. their receivers on their; switchhooks.

The replac al ofthe calling subscribers receiver causes the deenergization of relay {18, and thereplacalofthe calledrsubscribers receiver results in the de-energization of relay 43. Thede-energization ot relay 18 cans sin turn'tho, de-fle'nergization of relay 44,5. Theyoperation o f zither supervisory signals' (not shownijcontrolledby relays 48 grounded battery, power gmagnet' of sequence into position 18.- i

terminal: 40; lower distribution of the impulses. energiz'edwhen' the operator first inserted plug 5 into jackfi, 2 4 V Thenconnection 'is no .longer" desired,--

vquence switch spring 18, armature and back contact of relay 7 toground, for moving this sequence switch out ofposition 16 and Iii-position '18 oat-sequence switch 17, a

circuit is completed: from grounded battery, winding of stepping magnet 65, armature and contact ofmagnet 65," upper contact'of sequence switch spring Tet, oli-normal vcontact of wiper 75,.wiper 75, armature and back c mmemorrelay: 66:toground Stepand interrupts its own; circuit to advance the switch wipers one-step Magnet -;con-

position at which time the circuit wiper will be opened l Vhe-n; the auxiliary] switch :reaches its normal position, a circuit is completed from" Vgrounded battery, 'winding of down drive magnet 49, contactofsequence switchspring 1 50, wiperl 7 5. and, its normal contact, armature and back; contact of relay 66 to ground. The brush shaft is'-'r,eturned to its normal :position under: the control of 'magnet 19 i and as soon as commutator brush 21 engages normal commutator "segment -51, a circuit is completed from grounded battery, winding 20f power magnet of sequence switch 17, lower contact of sequence switch spring 52, commutator segment 51, commutator brush 21 to ground, for moving'se quence switch 17 out of position-1'81 andinto position 1.

As soon1as=the brush setleaves the termi- 'nals of the trunk, the releaseof the succeeding switches v-in tlietraintakes place in the "well" knownfmanner.

i "It: is obvious ,that only one interrupting .device isrnecessaryito :supp'lyzimpulses to all the outgoinglin'es in any exchange. -The operation, of the; pick-up, interrupter wheel will-preventany' possible confusion in the Connection to the. various outgoing-lines from the interrupter brushes maybe made through any desired, 1 Well known form of cross connectingframes lvhatisclaimed Y V 1. In a telephone exchange system, incoming lines, outgoing lines, a link circuit to be usedin establishing connection between an incoming line and an outgoing line, a repeating coil associated with said link circuit,'said repeating coil comprising a pri- :marywinding and asecondary winding, a

switching device for varying the ratioof the.

outgoing lines" to"supply impulses to con trol the operation ofsaid switching device, 12.111 a telephoneexchange system, in-

ine ma net 65 is ener ized in this circuit b b v number of turns ot' 'said secondary Winding to; the number *of J-turns of said primary, winding, and means-associated with said tween an incoming line and an outgoing line, a-repeating coil associated withsaid link circuit, said repeating coil comprising a primary winding and a secondaryfwinding, a switching device forvarying the ratio of the number of turns of said secondary winding to the number of turns of said primary winding, animpulse producing device common to said outgoing lines,

I and means for positioning said switching -dev1ce under the control of said lmpulse producing dGVlCQWhGIrCOIiHQOtlOII1S estab- I lished from anincoming line to' an outgoing line by means of said link-circuit. r i L I 3. Ina telephone exchange system, an automatic switch comprising a set of movable contacts and a plurality of sets of station- 'ary contacts, a link circuit terminating in; said movable contact set, a plurality of out-c going lines terminating in said stationary contact sets, means to supply series of impulses to said contact sets,'said series of impulses varying in; number in accordance with thecharacter of said outgoing hnes, a repeating coil associated with said link-cir-- cuit, said repeating coil comprising aiprimary winding and a secondaryxwinding,

- and a switching device'variably responsive to said series of impulses to" vary the ratio of the number of turns of said secondary winding to the number jot turns of s'aidpnmary winding. I V 7 o.

4. In a telephone exchange'system, an automatic switch comprising a set of movable contacts and a pluralityofstationary contact sets, a link circuitterminating in'said movable contact set, a plurality of outgoing lines terminating in said stationary contact sets, a progression controlling device, an

auxiliary switch associatedwith saidautomatic switch, means to operate said automatic switch in a hunting movement to select an outgoing line which-is in a desired I condition, a repeating coil associated with said link circuit, said repeating coil comprislng a primarywinding and a secondary winding, and means operative: in a certain 'pOS1t1011 of sa d progression controllingdevice to advance said'auxiliary switch in accordance with characteristics of the selected outgoing lines terminating in said stationary contact sets a progressionswitch and" .an auxiliary 'step -by-step switch associated withisaid automatic switch, means 'to'o peiz ate said automaticswit'chin ahunting movement to select an outgoing line in a desired condition, a repeating coll associated with said link, circuit, said repeating-coilcomprising,arprimarywinding anda secondary V winding, and means to supply a variable number of impulses in accordance with the characterfof the outgoingline selected to operate said step-by-step auxiliary switch to'vary the ratio of'the number of turns of said secondary winding to theinumber of turns ofsaid primarywinding.

6. In" a telephone exchange system, incom- 'ingzlines, means to transmit voice currents over said incoming lines, outgoing lines, av

link circuit-to be usedin establishing conmotion between an incoming line and an outgoing l1ne,a devlceassociatedwith sa d link circuit, said device being" arranged to modify voice currents received over said in-L 7 coming. line, a switch device, for varyingthe degree of modification of said voice currents, and means associated withsaid out going lines .to' supply impulses to control] '7 j the operation of said said'switching device.

' In, witness whereof, I hereunto subscribemy name this 23 day ofAug., A. D. 1920.

ALBEN LUNDELL.

so a 

